I generally agree with the immediately prior post. I might add a few other thoughts....

The St Regis feels quite like it was shoe-horned into a building from another era. The rooms, at least those that I'm familiar with, are quite small.

I like the RC-DC (distinct from the Georgetown property) for a business district hotel. They have several David Kroll paintings in their public areas (as do a few RCs, including PB)...we have several of his works at home and seeing them at the RC always makes me feel a little more at home. (I recognize I'm one of the few people, if not the only person, who derives this benefit. Check them out while you're there!)

I'm also a fan of the MO. I think this puts me well into the minority on this board...and indeed it's location isn't ideal (except if you're doing business with the Agriculture Department or want to be very close to the Jefferson Memorial)...but across half a dozen stays, I have had consistently spot-on service there. I've been given suite upgrades via FHR and find the spa to be great...and scarcely used. The extra FHR amenity at the MO is $85 towards the spa...I've been told conflicting things as to if this is for service or goods, but if you ask nicely, they seem to let you use it for whatever you'd like.